as in treacherous
formal
causing harm in a way that is gradual or not easily noticed
Most people with this insidious disease have no idea that they are infected. an insidious enemy
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Recent Examples of insidious
But, as outlined in the memo, its most insidious role is as a covert arm of Venezuela’s security state—used to assassinate dissidents, threaten exiled opposition figures, and weaponize migration as a geopolitical tool.
—
Antonio Maria Delgado, Miami Herald, 29 May 2025
In this moment of arbitrary tariffs and plummeting 401(k)s, banal conspicuous consumption has begun to feel insidious in its own way.
—Daniel Fienberg, HollywoodReporter, 8 May 2025
How To Break Down the 'Infinite Workday' Peak Hours Hijacked by Meetings
The timing of meetings creates a particularly insidious problem.
—Caroline Castrillon, Forbes.com, 18 June 2025
That principle ensures that all litigants in disputes have a voice with an open-minded audience and that the outcomes of cases, correct or not, are based on law and facts, not the insidious influence or pressure of external forces.
—Michael McAuliffe, Sun Sentinel, 10 June 2025
See All Example Sentences for insidious
Antonio Maria Delgado, Miami Herald, 29 May 2025
In this moment of arbitrary tariffs and plummeting 401(k)s, banal conspicuous consumption has begun to feel insidious in its own way.
—Daniel Fienberg, HollywoodReporter, 8 May 2025
How To Break Down the 'Infinite Workday' Peak Hours Hijacked by Meetings
The timing of meetings creates a particularly insidious problem.
—Caroline Castrillon, Forbes.com, 18 June 2025
That principle ensures that all litigants in disputes have a voice with an open-minded audience and that the outcomes of cases, correct or not, are based on law and facts, not the insidious influence or pressure of external forces.
—Michael McAuliffe, Sun Sentinel, 10 June 2025
See All Example Sentences for insidious
Recent Examples of Synonyms for insidious
Adjective
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And yes, much of it involves harrowing drives on treacherous mountain roads, only a few of which — disappointingly, considering the title — are icy.—
Frank Scheck,
HollywoodReporter,
26 June 2025
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But only three of those runs were earned, and three of the hits were pop flies missed due to treacherous winds at Wrigley.—
Sahadev Sharma,
New York Times,
22 June 2025
Adjective
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They are intended to reduce trauma to the scalp, may contribute to smoother recovery, and are designed to help achieve subtle, natural-looking outcomes.—
Daniel Fusch,
USA Today,
12 July 2025
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The property’s subtle musical motif reminds guests of its beginnings as a radio station, while the sunset libations at its Hi-Fi Rooftop Bar draw a regular crowd.—
Katie Strasberg Rousso,
Southern Living,
12 July 2025
Adjective
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The Federal Motor Carrier Safety Administration report said that driver also made a false report related to hours of service.—
Matthew Adams,
Fort Worth Star-Telegram,
3 July 2025
-
His claims are false and do not reflect accountability for the impact of his actions on the community.—
Marley Malenfant,
Austin American Statesman,
3 July 2025
Adjective
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The suit alleges excessive fees resulting in high annual percentage rates, deceptive tipping practices and misleading consumers about the voluntary nature of fees.—
AJ Dhaliwal,
Forbes.com,
9 July 2025
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Mayes seeks to dissolve both companies, citing violations of the Arizona Consumer Fraud Act and deceptive practices targeting underage customers.—
Jose R. Gonzalez,
AZCentral.com,
9 July 2025
Adjective
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Those voting for it are Sean Elo-Rivera, Jennifer Campbell, Kent Lee, Stephen Whitburn, Vivian Moreno and La Jolla’s own Joe LaCava, who has been an active supporter of this perfidious plan.—
Inga,
San Diego Union-Tribune,
16 June 2025
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Jake Gyllenhaal is his foil as the perfidious Iago, who goads Othello into unreasoning jealousy with lies about his beloved Desdemona (Molly Osborne).—
New York Times,
New York Times,
17 Feb. 2025
Adjective
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Rumors the man lost a limb are incorrect, friends of the victim with Raw Surf posted on the business' Facebook page.—
Natalie Neysa Alund,
USA Today,
8 July 2025
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An online commercial real estate site, LoopNet.com, still showed the theater property as up for auction Thursday, but Robinson said the listing is incorrect.—
Phil Diehl,
San Diego Union-Tribune,
6 July 2025
Adjective
-
However, according to the Baseball Rules Academy, the umpires got the call wrong.—
Ryan Canfield,
FOXNews.com,
5 July 2025
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One of the company’s big assumptions about the phone had turned out to be wrong.—
Verne Kopytoff,
Fortune,
5 July 2025
Cite this Entry
“Insidious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/insidious. Accessed 15 Jul. 2025.
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